Resins prepared from aromatic hydrocarbons

ABSTRACT

POLYMER PRODUCTS ARE PRODUCED BY DISTILLING A FULL RANGE DRIOLENE TO REMOVE AN OVERHEAD PRODUCT BOILIN BELOW ABOUT 140 TO 160* F. AND A BOTTOMS PRODUCT BOILING ABOVE 245 TO 250*F., AND AN INTERMEDIATE PRODUCT BOILING BETWEEN THESE TWO MATERIALS, THE OVERHEAD AND BOTTOMS ARE COMBINED, POLYMERIZED, AND DISTILLED TO RECOVER A RESIN BOILING ABOVE 350*F., AND THE INTERMEDIATE PRODUCT IS EITHER HYDROGENATED OR DEHYDROGENATED AND THEREAFTER POLYMERIZED IN AT LEAST ONE STAGE OF POLYMERIZATION AND DISTILLED TO RECOVER A RESIN PRODUCT BOILING ABOVE ABOUT 245*F.

March 14, 1972 M. KOVACH ETAL 3,649,517

RESINS PREPARED FROM AROMATIC HYDROCARBONS Original Filed Sept. 28, 1966Benzene-To|uene Recovery 74 72 86 H2 5% BO 'l-C4 l I4 70 i 64 85 1 42 PP D (30 Y E O O 82 D Feed l D Y L L J I Mixture S 8 D Y Y i T as G 54 RM M I E E IO L E E R R 38 v L A N J g E E E 34- 88 i 7s 6 44 90 /I6Resin 76J 361 1 Z 46 L50 P O D 20 24 E T R I g L L E A22 Resin INVENTORSStephen M Kovoch Ralph E. Patrick ATTORNEY United States Patent 93,649,517 RESIWS PREPARED FRQM AROMATIQ HYDROCARBONS Stephen M. Kovach,Ashland, and Ralph E. Patrick, Flatwoods, Ky., assignors to Ashland Oil,Inn, Houston, Tex. Continuation of application Ser. No. 582,754, Sept.28, 1966. This application Dec. 29, 1969, Ser. No. 888,160 Int. Cl. C08f15/42 US. Cl. 20822 8 Claims ABSTRACT OF THE DISCLOSURE Polymer productsare produced by distilling a full range dripolene to remove an overheadproduct boiling below about 140 to 160 F. and a bottoms product boilingabove 245 to 250 F., and an intermediate product boiling between thesetwo materials, the overhead and bottoms are combined, polymerized, anddistilled to recover a resin boiling above 350 F., and the intermediateproduct is either hydrogenated or dehydrogenated and thereafterpolymerized in at least one stage of polymerization and distilled torecover a resin product boiling above about 245 F.

The present invention relates to the production of resins from aromatichydrocanbons and the products thereof. In a more specific aspect thepresent invention relates to the production of resins from normallyliquid hydrocarbon mixtures containing aromatics, mono-olefins anddiolefins and the novel products thereof. in a still more specificaspect the present invention relates to the production of resins fromdripolene and the novel products thereof.

Normally liquid hydrocarbon mixtures containing aromatics, mono-olefinsand diolefins are produced by a variety of well known processes. Suchprocesses include the pyrolysis or cracking of crude petroleum orfractions thereof containing at least two carbon atoms such as ethane,propane, propylene, butane, natural gasoline, light straight rungasoline, straight run naphtha, kerosene, light cycle oils produced inthe cracking of gas oils to produce gasoline, straight run gas oil, etc.These processes are carried out with or without the aid of catalysts andin the presence or absence of steam. Generally, the reaction temperatureis in the neighborhood of about 1350 to 1550 F. and the pressure may befrom to 50 p.s.i.g. or higher. Such pyrolysis operations are generallycarried out, primarily, for the production of ethylene. The pyrolysis ofhydrocarbons to produce ethylene results in a normally gaseous productcontaining unsaturated hydrocanbons; including, ethylene, normallyliquid hydrocarbons rich in unsaturated hydrocarbons including olefinsand diolefins of varying boiling points and structures, and variousaromatic hydrocrabons, as well as tar. The normally liquid hydrocarbonsand tar obtained from this process are considered by-products. Thesebyproducts are removed by rapidly cooling the pyrolysis products,usually by quenching with water to a temperature of about 400 F. Aviscous tarry material condenses out of the gas during the quenchingoperation. Gases from the quenching operation are then compressed andcooled and a liquid material boiling between about 100 and 360 F.condenses out of the gases during the compression-cooling operation.This last material is known as dripolene.

Dripolene fractions obtained in the manner set forth normally containabout two-thirds aromatics and onethird non-aromatics, the latter beingmostly olefins and ice diolefins. The aromatic portion consists mainlyof henzene and toluene both of which are valuable in their own right andwhich are normally recovered. Such benzenetoluene concentration isusually accomplished by removal of the unsaturated compounds from thedripolene or by the removal of the aromatics selectively. Aromaticremoval has heretofore been practiced by selective adsorption onmaterials, such as, silica gel, activated alumina, etc. However, suchselective adsorption of aromatics is not effective since diolefinsbehave quite similarly to the aromatics. Generally, the removal of theunsaturated compounds is practiced commercially by hydrogenation orpolymerization of the dripolene. Hydrogenation and polymerization toremove unsaturates from aromatics are also inefiicient and producelittle in the Way of valuable products. Normally the hydrogenation ofdripolene pro duces substantial amounts of mono-olefins which uponpolymerization do not yield resins having any real value. Polymerizationof dripolene is practiced commercially by either thermal or catalytictechniques. Thermal po lymerization of the dripolene yields resinproducts which contain substantial amounts of cyclic diolefins andnormally has no elfect on the acyclic diolefins and tertiarymono-olefins present. On the other hand, catalytic polymerization ofdripolene, under normal conditions of temperature, pressure andcatalyst, yields resins containing substantial amounts of aromatics.

Another convenient source of aromatic hydrocarbons, particularly benzeneand toluene is an aromatic light oil obtained by the high temperaturecarbonization of coal. The products of this carbonization are coke andthe aromatic light oil. This light oil contains relatively highconcentrations of unsaturates, sulfur and nitrogen compounds in additionto benzene, toluene and xylene. For example, a coal tar light oilboiling in the range of about ISO-300 F. will contain, roughly,benzenetoluene and about 15% unsaturates and impurities. Heretofore, therecovery of aromatics from coal tar light oils, particularly therecovery of benzene, has been effected by acid washing with sulfuricacid, \benzene crystallization followed by acid washing, hydrotreatingfollowed by solvent extraction with an aromatic-selective solvent orhydrotreating followed by high severity hydrocracking. Each of thesetreatments has been found to have its own peculiar drawbacks. Forexample, acid treating alone results in a benzene product of high puritywith a high thiophene content. Benzene crystallization followed by acidwashing will produce a product of high purity having a low thiophenecontent, but, by the same token, the recoveries of benzene are low.Hydrotreating followed by solvent extraction produces a high puritybenzene product but is a costly process and coking problems in thepreheater to the hydrotreater exist. The final technique ofhydrotreating followed by high severity hydrocracking is a costlyproposition because of the high pressures and high temperatures involvedand at times such treatment does not produce specification gradebenzene.

As previously indicated hydrogenation or polymerization of wide boilingrange fractions of aromatic hydrocarbon mixtures, such as, dripolene andcoal tar light oils, does not produce resins which are suitable for useas drying oils. There is either no drying oil production, as in the caseof hydrogenation followed by conventional polymerization; or resinscontaining substantial amounts of aromatics are produced, as in the caseof catalytic polymerization under conventional conditions; or, finally,resins containing cyclic diolefins result, as by thermal polymerizationunder conventional conditions.

The process of the present invention has been found to produce resinssubstantially free of aromatics or cyclic diolefins and which are,therefore, excellent drying oils.

The following specific examples will illustrate the present invention.

Referring to the drawings an aromatic feed mixture containing at leastabout 50% aromatics and less than about 50% non-aromatics, consistingessentially, of olefins and diolefins is utilized. By way of specificexample, dripolene obtained as a by-product in the thermal pyrolysis ofgaseous hydrocarbons to produce ethylene will be referred to. Thisdripolene fraction comprises about 75% by volume of material boilingthrough the boiling range of toluene (about 230 F.) and about 25% byvolume of material boiling above the boiling range of toluene. Of thismaterial approximately 39.9% is benzene. This feed mixture is first fedthrough line 10 to a distillation column 12. In distillation column 12the feed mixture is split into a heart out having a boiling range ofabout 140 to 250 F. and preferably between about 160 and 245 F. Materialboiling below about 160 F. is discharged from the column through line 14while matoluene fraction may be fed to polymerization column 34. Inpolymerization reactor 34 the benzene-toluene fraction may be subjectedto polymerization in the presence of an acidic, solid oxide catalyst,particularly boriaalumina and silica-alumina. Other such catalystsinclude silica-magnesia, fluoride promoted alumina, etc. Thepolymerization should be carried out at a temperature between about and300 F., and preferably 50 to 250 F. at a pressure between about 0 and3000 p.s.i.g., preferably between about 0 and 1000 p.s.i.g., and at aliquid hourly space velocity (LHSV) between about 0.1 and 10, andpreferably between about 0.5 and 5.

Table I below shows the results of a series of polymerizations of fullrange dripolene, containing 75% by volume of material boiling throughthe boiling range of toluene and 25% boiling above toluene, and theheart cut fraction of the present invention, containing 100% by volumeof material boiling through the boiling range of toluene, respectively,utilizing both silica-alumina and boria-alumina tenal boiling aboveabout 245 F. is discharged through 20 catalysts.

TABLE I Run number l 2 3 4 Feed Raw dripolene... Raw dripolene Heart-cutHeart-cut dripolene. dripolene. Catalyst IOBzOz-AlzOa slorAlzQauflu.log-A1 03 IOBzOz-AlgOa. Temperature r.) 120... 120- 160.... 160.Pressure {p.sig.) 0 0.. 100. LHSV 2 1.. 1. Product (percent):

Benzene 39.0 40.0 70.0 688 Toluene 28.0 25.0 30.0 31 2 Resin 8.0 10.010.5 10.5. Toluene 25.0 25.0 0.0 0.0.

line 16. The fraction boiling below benzene (about 160 F.) is combinedwith the fraction boiling above toluene (about 245 F.). These combinedfractions are fed through line 18 to polymerization reactor 20. Inpolymerization reactor 20 the material is processed under selectpolymerization conditions to insure that no aromatics are incorporatedinto the resin product. These conditions; include, 0 to 3000 p.s.i.g.and preferably about 0 to 1000 p.s.i.g.; a temperature in theneighborhood of about 0 to 300 F. and preferably about 50 to 250 F; anda liquid hourly space velocity of about 0.1 to and preferably about 0.5to 5.0. By way of specific example, a pressure of about 100 p.s.i.g., atemperature of about 200 F. and a LHSV of about 1.0 produce outstandingresults. The catalyst is preferably 2 to boria on alumina orsilicaalumina. However, any acidic, solid oxide catalyst includingsilica-magnesia, fluoride promoted alumina, etc. can be used. Theproduct of polymerization column is discharged through line 22 and is inturn fed to distillation column 24. In distillation column 24 thematerial is processed to remove unconverted material and leave thedesired resin as a distillation bottoms boiling below about 350 F.Accordingly, unconverted material is discharged through line 26 and thedesired resin product through line 28. The resin yield obtained underthe conditions set forth above was approximately 33 by volume of thetotal feed to distillation column 24 and is substantially free ofaromatics. A single polymerization of this material is carried out sincefurther processing leads to the production of olefin polymers andalkylated aromat ics, apparently due to the absence of diolefins in thepolymerization column. It appears that substantially complete removal ofthe diolefins occurs in column 20 during a single pass through thereactor.

The benzene-toluene cut boiling between about 160 and 245 F. isdischarged from distillation column 12 through line 30. Thebenzene-toluene fraction can also be treated in several alternativefashions to produce additional amounts of aromatic-free resins.

One method of further treating the benzenc-toluene fraction is by theselective polymerization of this fraction. Specifically, by openingvalve .32 in line the benzene- It is clear from Table I that there is anet loss of aromatics when the full boiling range dripolene is treatedand hence the resin product of this treatment Will contain substantialamounts of aromatics. By way of contrast, aromatic recovery isessentially quantitative when the heart-cut of dripolene is polymerized,thus indicating that the resin product is substantially free ofaromatics.

The polymerization product of column 34 is discharged to line 36 and isfed to distillation column 38 by opening valve 40. In distillationcolumn 38 the product is separated into a fraction boiling below about245 F. and a resin product boiling above about 245 F. The formerproduct, which contains benzene and toluene, is fed to an appropriatebenzene-toluene recovery operation through line 42 while the resinproduct boiling above about 245 F. is discharged through line 44. Theresin product discharged through line 44 may be utilized as such, bywithdrawing the same through line 46, or it may be combined with theresin product of polymerization column 2.9 by discharging the samethrough line 48. Where such blending is desired valve 50 would be closedand valve 52 would be open. The combined resin material would be fed todistillation column 24 where it would be further treated to recover aresin product boiling above about 350 F.

In another technique for recovering a valuable resin product from thebenzene-toluene fraction being discharged through line 30, the heart outmixture is first dehydrogenated in dehydrogenation reactor 54. For thispurpose the benzene-toluene fraction is fed to column 54 through line 56by closing valve 32 and opening valve 58. In dehydrogenation column 54the heart cut fraction is dehydrogenated under conventional conditionsto convert cyclohexadienes to aromatics. Suitable conditions for theoperation of the dehydrogenator; include, the use of an activehydrogenation-dehydrogenation metal, including, those from Groups V-A,VI-A, VIII, I-B and iI-B, on a neutral or basic support, such asalumina, silica, spinels, etc., for example, between about 0 and 500 F.,and, preferably, 3 to 50% chromia on alumina, etc.; a temperature aboutl00-300 F.; a pressure of about 0 to 1000 p.s.i.g., and, preferably,about 0 to p.s.i.g.; and

a liquid hourly space velocity of about 0.1 to 10, and, preferably,about 0.5 to 2. The product from dehydrogenation column 54 is dischargedthrough line 60 and is passed to polymerization column 34, by openingvalve 62 and feeding the material to line 64. In column 34 thedehydrogenated heart cut fraction is treated under essentially the sameconditions previously set forth. After polymerization, the polymerizatepasses to distillation column 38 where it is separated to recover theresin fraction boiling above about 245 F. Table 11 below shows theresults of dehydrogenating a heart out fraction. This heart cut fractioninitially contained 10.5% benzene, 76.0% benzene, 12.9% toluene and 2.7%toluene. Of this feed about 2.7% were cyclohexadienes.

TABLE II Feed Heart-cut dripolene. Catalyst CI'203A1203- Temperature, F300. Pressure p.s.i.g. 0. LHSV 0.75. Product:

Benzene 7.8 Benzene 78.5.

Toluene 13.3.

Toluene 0.4. Cyclohexadiene 0.1.

Yet another method of recovering valuable resin products from the heartcut fractions passing through line 30 is by the hydrogenation of thismaterial followed by polymerization. In this instance the heart cutfraction is charged to hydrogenation column 66 through line 68 which iscontrolled by valve 70. Hydrogen is supplied through line 72 and valve 74 from an external source not shown. Hydrogenation is, preferably,carried out in the presence of about 0.1 and 10% rhenium heptoxide onalumina as a catalyst. In the course of processing high sulfur feedmaterials the rhenium heptoxide will be converted to rheniumheptasulfide or its lower sulfides. The sulfide can also be producedprior to use of the catalyst by treating rhenium heptoxide with hydrogensulfide. Other suitable catalyst, include, platinum or palladium onalumina, etc. The hydrogenation treatment is preferably carried out at atemperature of about 100 to 300 F. although temperatures from 75 to 400F. can be used. A pressure in the range of zero to 3000 p.s.i.g. may beused, and preferably one between zero and 1000 p.s.i.g. The liquidhourly space velocity (LHSV) should be between 0.1 and 10, andpreferably between 0.5 and 2, while a hydrogen rate between 100 and 1000cubic feet per barrel of feed and preferably between 100 and 300 cubicfeet is used. The hydrogenation product is discharged through line 76 byopening valve 78. From line 76 the hydrogenation product passes to line64 and thence to polymerization column 34. From polymerization column 34the polymerization product passes to distillation column 38 where it istreated in the same manner as previously described.

The following table illustrates the results of hydrogenating a heart outdripolene, containing, 10.6% benzene, 74.8% benzene, 14.1% toluene and0.5% toluene, and had a bromine of 24.9.

TABLE I11 Feed Heart cut dripolene. Catalyst 0.5% ReAl O Temperature F.300. Pressure, p.s.i.g 0. LHSV 0.75. H ftfi/bbl 200. Product:

Benzene, percent 9.0.

Benzene, percent 75.0.

Toluene, percent 15.0.

Toluene, percent 1.0.

Bromine 11.1.

Yet another means of treating the heart-cut fraction passing throughline 30 is by a combination of selective polymerization treatments. Inthis series of treatments the heart-cut fraction is treated in column 34by the low severity polymerization treatment previously described. Fromcolumn 34 the polymerization product is discharged through line 36 andthence to line 80. This material is fed to second polymerization column82 by opening valve 84 in line 80. The small volumes of unsaturatesremaining after polymerization in column 34 are primarily secondaryolefins having normal or branch chains. Further polymerization of theseolefins could be accomplished under severe conditions to effect completeolefin removal. However, such severe polymerization would normally leadto aromatic alkylation and a consequent loss of valuable benzene andtoluene as well as contamination of the resin product. Accordingly, incolumn 82 the polymer product of column 34 is subjected topolymerization in the presence of an acidic solid oxide catalyst and atertiary olefin. The tertiary olefin is introduced through line 85 andvalve 86. When secondary olefins are treated with acidic catalysts theyyield secondary carbonium ions which undergo aromatic alkylation asreadily as polymerization. However, by introducing the teritary olefin,tertiary carbonium ions are produced which drive the reaction towardpolymerization rather than aromatic alkylation. In polymerization column82 the catalyst may be any acidic solid oxide catalyst, silica-alumina,boria-alumina, silicamagnesia, fluoride promoted alumina, etc. and thetertiary olefin may be any olefin in the range of C to C and theirdimers, especially isobutylene and isoamylene. Temperature conditionsappropriate to this reaction are zero to 300 F. and preferably 50 to 200F. The pressure should be maintained between 0 and 1000 p.s.i.g. andpreferably between 50 and 200 p.s.i.g. The liquid hourly space velocity(LHSV) should be between 0.1 and 10 and preferably between 0.5 and 2. Atertiary olefin to feed ratio (volume/volume) of l/1-1000 and preferably1/10-100 should be utilized. A comparison of the polymerization of afraction, boiling between 160 and 245 F., from a first polymerizationtreatment is shown in the following table, where the secondpolymerization was carried out with a silica-alumina catalyst, at 160F., at 100 p.s.i.g. and at a LHSV of 1.0. This feed comprised; 12.6%benzene, 73.2% benzene, 14.2% toluene and 0.0% toluene.

The product of polymerization column 82 is discharged through line 88and valve 90 and thence the distillation column 38 where it is furtherprocessed to separate the benzene-toluene fraction and the resin productboiling above about 245 F.

Toluene.

We claim:

1. A resin product obtained by distilling a hydrocarbon mixture selectedfrom the group consisting of dripolene, having a boiling range of about-360 F., and coal tar light oil, having a boiling range between aboutand 300 F., to remove a benzene-toluene concentrate, having a boilingrange between about F. and 245 F., recombining the fraction boilingbelow 160 F. and the fraction boiling above 245 F., subjecting saidrecombined fractions to polymerization in the presence of anacidic-solid oxide catalyst at a temperature of about 0 F. to 300 F. apressure of about 0 to 3000 p.s.i.g., and a liquid hourly space velocitybetween about 0.1 and 10, and distilling the polymerization product torecover a resin boiling above about 350 F.

2. A product in accordance with claim 1 wherein the hydrocarbon mixtureis dripolene.

3. The product in accordance with claim 1 wherein the hydrocarbonmixture is coal tar light oil' 4. A resin product obtained by distillinga hydrocarbon mixture selected from the group consisting of dripolenehaving a boiling point between about 100 and 360 F., and coal tar lightoil having a boiling point between about 150 and 300 F., to obtain abenzene-toluene concentrate, having a boiling range between about 160and 245 F., subjecting said benzene-toluene concentrate topolymerization in the presence of an acidic, solid oxide catalyst at atemperature of about to 300 F., a pressure of about 0 to 3000 p.s.i.g.,and a liquid hourly space velocity of about 0.1 to combining thefraction boiling below 160 F. and the fraction boiling above 245 F.;polymerizing said combined fractions in the presence of an acidic, solidoxide catalyst at a temperature of about 0 to 300 F., a pressure ofabout 0 to 3000 p.s.i.g., and a liquid hourly space velocity of about0.1 to 10; combining the products of the first polymerization and thesecond polymerization steps; and distilling said combined products ofsaid polymerization steps to recover a resin boiling above about 245 F.

5. A resin product obtained by distilling coal tar light oil having aboiling point between about 150 and 300 F., to obtain a benzene-tolueneconcentrate, having a boiling range between about 160 and 245 F.,subjecting said benzene-toluene concentrate to polymerization in thepresence of an acidic, solid oxide catalyst at a temperature of about 0to 300 F., a pressure of about 0 to 3000 p.s.i.g., and a liquid hourlyspace velocity of about 0.1 to 10, and distilling the polymerizationproduct to recover a resin boiling above about 245 F.

6, A resin product obtained by distilling a hydrocarbon mixture selectedfrom the group consisting of dripolene having a boiling range of about100 to 360 F and coal tar light oil boiling between about 150 and 300F., to obtain a benzene-toluene concentrate, having a boiling range ofabout 160 to 245 F., subjecting said benzenetoluene concentrate todehydrogenation in the presence of an activehydrogenation-dehydrogenation metal deposited on a base selected fromthe group consisting of a neutral and a basic material at a temperatureof about 0 to 500 F., a pressure of about 0 to 1000 p.s.i.g., and aliquid hourly space velocity of about 0.1 to 10, subjecting thedehydrogenation product to polymerization in the presence of an acidic,solid oxide catalyst at a temperature of about 0 to 300 F., a pressureof about 0 to 3000 p.s.i.g., and a liquid hourly space velocity of about0.1 to 10; combining the fraction boiling below 160 F. and the fractionboiling above 245 F.; subjecting said combined fractions to a secondpolymerization in the presence of an acidic, solid oxide catalyst at atemperature of about 0 to 300 F., a pressure of about 0 to 3000p.s.i.g., and a liquid hourly space velocity of about 0.1 to 10;combining the first and the second polymerization products; anddistilling said combined products of said polymerization steps torecover a resin boiling above about 245 F.

7. A resin product obtained by distilling a hydrocarbon mixture selectedfrom the group consisting of dripolene having a boiling range of aboutto 360 FL, and coal tar light oil having a boiling range of about to 300F2, to obtain a benzene-toluene concentrate boiling between about and245 F, subjecting said benzenetoluene concentrate to hydrogenation inthe presence of hydrogen and a hydrogenation catalyst at a temperatureof about 100 to 300 F., a pressure of about 0 to 3000 p.s.i.g., and aliquid hourly space velocity between about 0.1 and 10, subjecting thehydrogenation product to polymerization in the presence of an acidic,solid oxide catalyst at a temperature of about 0 to 300 F., a pressureof about 0 to 3000 p.s.i.g., and a liquid hourly space velocity of about0.1 to 10; combining the fraction boiling below 160 F. and the fractionboiling above 245 F; subjecting said combined fractions to a secondpolymerization in the presence of an acidic, solid oxide catalyst at atemperature of about 0 to 300 F, a pressure of about 0 to 3000 p.s.i.g.,and a liquid hourly space velocity of about 0.1 to 10; combining theproducts of the first and the second polymerization steps, anddistilling said combined products of said polymerization steps torecover a resin boiling above about 245 F.

8. A resin product obtained by distilling a hydrocarbon mixture selectedfrom the group consisting of dripolcne boiling between about 100 and 360F., and coal tar light oil boiling between about 150 and 300 F., toobtain a benzene-toluene concentrate boiling between about 160 and 245 Fsubjecting said benzene-toluene concentrate to polymerization in thepresence of an acidic, solid oxide catalyst at a temperature of about 0to 300 F., a pressure of about 0 to 3000 p.s.i.g., and a liquid hourlyspace velocity between about 0.1 and 10, subjecting the polymerizationproduct to a second polymerization in the presence of a tertiary olefinfrom an external source, in a ratio of tertiary olefin to hydrocarbonmixture of about 1:1 to 111000, and in the presence of an acidic, solidoxide catalyst at a temperature of about 0 to 300 E, a pressure of about0 to 3000 psig, and a liquid hourly space velocity of about 0.1 to 10;combining the fraction boiling below 160 F. and the fraction boilingabove 245 F; subjecting said combined fractions to polymerization in thepresence of an acidic, solid oxide catalyst at a temperature of about 0to 300 F., a pressure of about 0 to 3000 p.s.i.g., and a liquid hourlyspace velocity of about 0.1 to 10; combining the polymerization productsof the second and the third polymerization steps; and distilling saidcombined products of said polymerization steps to recover a resinboiling above about 245 F.

References Cited UNITED STATES PATENTS 2,353,596 7/1944 Shifiler et al.260-6834 2,733,284 1/1956 Hamner 260-674 2,733,285 1/1956 Hammer 260-6742,798,866 7/1957 Gordon et a1. 260-82 2,894,937 7/1959 Banes et al260-82 HERBERT LEVINE, Primary Examiner US. Cl. X.R.

